Electrical glow-lamp.



No. 666,602. Patented Ian. 22, 1901. A. COUCH.

ELECTRICAL GLOW LAMP.

(Application filed June 11, 1900.)

(No Model.)

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UNITED STATES PAT NT ()FFIQE.

ARTHUR COUCH, OF LONDON, ENGLAND.

ELECTRICAL G LOW-LAM P.

SPECIFICATION forming part of Letters Patent No. 666,602, dated January 22, 1901.

Application filed \Tune 11, 1900,

To all whom it may concern:

Be it known that I, ARTHUR COUCH, a citizen of England, residing at 190 Brixtou road, London, England, have invented a certain new and useful Improvement in Electrical Glow-Lamps, of which the following is a specification.

This invention relates to the construction of an electrical glow-lamp in such a manner that it can be made at will to give out either of two differently-colored lightssuch as a white and a green or red, or both together as I shall describe, referring to the accompanying drawings.

Figure 1 is a vertical section, and Fig. 2 is a plan, of a lamp according to my invention.

For this purpose a small glow-lamp having its bulb a of colored glass, such as a green or red. is introduced into the neck of a bulb b of plain glass which has in it a filament c. The leading-in wires cl of the filament c being passed through the narrowannular space between the necks of the two bulbs, this space is closed hermetically by the blowpipe, with these wires sealed into the glass. The four leading-in wires of the inner and the outer filaments are led through the ordinary insulating-filling e of the head to four separate contact-plates f, and the outer bulb is exhausted in the usual way, the inner tube being also exhausted through a small hole. The holder for such a lamp is the same as an ordinary holder, except that it has four spring- Serial No. 19,935- (No model.)

piston contacts instead of two. Each pair of these contacts being connected to a switch, current can be sent through either the inner or the outer filament, or through both.

Instead of four contact-plates, as above described, three contact plates may be employed, the two leading-in wires, one from the one end of each of the two filaments, being connected to a single contact-plate, while the wire from the other end of each filament is connected to a separate contact.

Having thus described the nature of this invention and the best means I know of carrying the same into practical effect, I clai m An electrical glow-lamp having an outer bulb of plain glass containing afilament, and within the outer bulb an inner bulb of colored glass also containing a filament, the necks of the two bulbs being sealed together including in the seal the leadingnvires of the filament of the outer bulb, and these wires as Well as the leading-in Wires of the filament of the inner bulb being led through the insulating-filling of the head to four separate contact-plates, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- HGSSBS.

ARTHUR COUCH. Witnesses:

GERALD L. SMITH, EDWARD GARDNER. 

